Adaptive microstrip phase shifter using ground plane slot structures [phased array beam steering applications]

An adaptive microstrip transmission line phase shifter is presented using slot structures in the ground plane, and an air gap beneath the glass substrate and ground plane membrane. This phase shifter provides a phase shift range between 180/spl deg/ to 206/spl deg/ at millimeter wave frequencies. The slot membrane structures can be moved by applying an electrostatic potential on the electrode. It can find applications in phased array antennas.